The present invention relates to a scroll compressor in which laps are formed on the mutually facing faces of a fixed scroll and a mirror plate of an orbit scroll which revolves in the orbit with respect to the fixed scroll, and the laps are engaged with each other to form a plurality of compression chambers.
Heretofore, this type of scroll compressor has a fixed scroll and an orbit scroll which revolves in the orbit with respect to this fixed scroll, spiral laps are formed on the mutually facing faces of the fixed scroll and a mirror plate of the orbit scroll, and the laps are engaged with each other to form a plurality of compression chambers.
A slide bush is interposed on an eccentric shaft of a motor which drives the orbit scroll. This slide bush has a slide face forming a predetermined angle with respect to the direction of gas load of a gas in each compression chamber. When the load of the gas in the compression chamber is applied, the eccentric amount of the eccentric shaft increases.
It is known that according to such a constitution, the slide face can exert the component force of the gas load to increase the eccentric amount, and hence seal properties between both the laps of the fixed scroll and the orbit scroll can be improved to improve the performance of the compressor (e.g., see Japanese Patent Application Laid-Open No. 7-71386) (Patent Document 1)).
As such a scroll compressor, a compressor is developed in which a spring member is interposed between the slide bush and the eccentric shaft, and the spring member presses the eccentric shaft in an eccentric direction, to decrease the eccentric amount at a start, thereby decreasing a load at the start.
Specifically, in the above scroll compressor, when the spring member presses the eccentric shaft in the eccentric direction, the eccentric amount decreases at a stop, and a clearance between both the laps increases, so that the start load can be decreased.
On the other hand, when the gas load starts to be applied, the slide bush moves against the urging force of the spring member in a direction where the eccentric amount of the eccentric shaft increases, so that an adequate eccentric amount can be obtained (e.g., see Japanese Patent No. 3165153 (Patent Document 2)).
However, in the scroll compressor in which the spring member presses the eccentric shaft in the eccentric direction as described above to obtain a variable eccentric amount of the eccentric shaft, a problem occurs that during an operation, the slide face of the slide bush comes away from the eccentric shaft to cause backlash.
The present invention has been developed to solve such a conventional technical problem, and an object thereof is to stabilize the moving of the orbit scroll while suppressing the start load of the scroll compressor.